Fizzbuzz implemented in Erlang

fizzbuzz.erl

%% DISCLAIMER: Please excuse my style, I don't write erlang.
-module(fizzbuzz).
-export([fizz_buzz/0]).

fizz_buzz() ->
  fizz_buzz(1).

fizz_buzz(N) when N =< 100 ->
  if
    N rem 15 == 0 ->
      io:format("fizzbuzz~n");
    N rem 5 == 0 ->
      io:format("buzz~n");
    N rem 3 == 0 ->
      io:format("fizz~n");
    true ->
      io:format("~p~n", [N])
  end,
  fizz_buzz(N + 1);

fizz_buzz(_) -> done.

fizzbuzz2.erl

%% DISCLAIMER: Please excuse my style, I don't write erlang.
-module(fizzbuzz).
-export([fizz_buzz/0]).

fizz_buzz() ->
  fizz_buzz(1).

fizz_buzz(N) when N > 100 ->
  done;

fizz_buzz(N) when N rem 15 == 0 ->
  io:format("fizzbuzz~n"),
  fizz_buzz(N + 1);

fizz_buzz(N) when N rem 5 == 0 ->
  io:format("buzz~n"),
  fizz_buzz(N + 1);

fizz_buzz(N) when N rem 3 == 0 ->
  io:format("fizz~n"),
  fizz_buzz(N + 1);

fizz_buzz(N) ->
  io:format("~p~n", [N]),
  fizz_buzz(N + 1).

Hey, cool, you've got a pretty solid grasp of some fundamental concepts here and, more interestingly, have found a place where Erlang's if clause actually makes a ton of sense. Kudos!

Personally, I like the fizzbuz.erl more. I like that its more compact so you can see the causal relationship with side-effect and trigger closely and I like that there's less duplication overall; the recursion is so similar you lose out in the function-clause style--fizzbuz2.erl---simply because the density of the idea is much, much less than the bulk of the code.

Were fizz_buz/1 exposed to a public consumer I would suggest that you might add an is_integer/0 guard clause, but since that function is purely internal there's no reason to bother. I generally like to put my internal functions off behind a comment block: example